Hail damaged cotton will delay maturity

What to do with a field of cotton after a hail event is often a difficult decision yet can also be simple.
Avoid going into the field for several days because cotton will look terrible the day after hail hit.
If the survivable plant population is greater than 20,000 plants per acre, and the stand is uniform I would keep it.

Jeffrey Stapper, Texas AgriLife | May 21, 2012

Recent storms dropped hail on some cotton in the Coastal Bend. Deciding what to do with a field of cotton after a hail event is often a difficult decision yet can also be simple.

Your best option is to avoid going into the field for several days because cotton will look terrible the day after hail hit. If weeds are an issue, give the cotton some time to recover before applying herbicides.

So when you do go back to the field what should one look for? When looking at a hail-damaged field, examine the plants to see what percent have a terminal loss and what percent are cut off below the cotyledon node. Those cut off below the cotyledon node probably will not recover. Those that do not have a terminal probably will recover but produce a crazy plant with many branches due to the loss of apical dominance. These plants can produce cotton but maturity will be delayed and will be subjected to problems associated with late cotton—insects, weather, and increased production cost with low potential returns.

If the survivable plant population is greater than 20,000 plants per acre, and the stand is uniform I would keep it. Plants with damaged terminals will develop new reproductive branches, which will set fruit and can reach 80 percent to 100 percent of the pre-hail yield potential. However, maturity will be delayed and pest and agronomic management must be adjusted for a late crop.

If the weather turns favorable after a hail storm, with timely rainfall plant recovery will be impressive. One reason is the increased root to shoot ratio. Following hail damage, the plant has a large relative root system to provide lots of nutrients and water to the smaller shoot with lower leaf area. The reduced leaf area and injured leaves are reasons why attempting to foliar feed hail damaged cotton has not been successful.

No miracle cures can be sprayed on the fields to increase survival or yields.

The very thing that makes cotton so complicated to manage, being an indeterminate perennial, gives cotton an advantage over other crops when hit by hail. Cotton can recover much better from hail damage than corn, for instance.

Hail damaged cotton will produce numerous vegetative branches and hail-damaged fields will also act like and need to be treated like late cotton. Assuming good growing conditions following the hail event, a plant growth regulator (mepiquat type product) likely will be necessary because they have a beneficial impact on this type of damaged cotton. These applications should be made after the cotton has recovered and branching and square set is occurring.

If we do not get the timely rainfall during the rest of the growing season, mepiquat products may not be needed.